Provide support to both the Carcinogenesis Program and to the NC Program by providing information on those chemicals with which man comes in contact. It serves to make available to program staff, as well as other interested parties, data and information on the structure, properties, use, production, distribution, and human exposure of such substances. In accomplishing this objective, it is expected that the contractor will acquire information which will assist program staff in: choosing those compounds having highest priority for entry into bioassay testing; identifying trends in the exposure of man to chemicals in his environment; exposures; and providing information support to the related activities of other organizations, both nationally and internationally.